Lamp base and socket

ABSTRACT

A special purpose electric lamp having a base of the bayonet type and a socket accommodating the base. A stop in the socket obstructs the insertion of a conventional bayonet lamp base into a locked position in the socket and the bayonet base of the special purpose lamp accommodates the stop in the locked position of the lamp in the socket.

0 United States Patent [11135 9307 ll'lVClltOl' B. FOREIGN PATENTS [21 1No 55$? Haws 286,852 3/1928 Great Britain 339/188 {22] Filed Aug 28,1968 Primary Examiner-Marvin A. Champion [45] Patented Mar. 9, 1971Assistant Examiner-Joseph H. McGlynn [73] Assignee General ElectricCompany Attorneys-Otto Ticky, Henry P. Trnesdell, Frank L.

[54] LAMP BASE AND SOCKET UNITED STATES PATENTS 2,906,986 9/1gs 9Schaefer Neuhauser, James J. Lazna, Oscar B. Waddell and Joseph B.Forman ABSTRACT: A special purpose electric lamp having a base of thebayonet type and a socket accommodating the base. A stop in the socketobstructs the insertion of a conventional bayonet lamp base into alocked position in the socket and the bayonet base of the specialpurpose lamp accommodates the stop in the locked position of the lamp inthe socket.

Patented March 9, 19 71 r I 3,569,907

Fig. 5.

I 31 mm Lt Z2 ITWVTWTOTI WiLLiaTn B. Landggvaf b9 0% 21 His Alttcn negLAMP BASE AND SOCKET The present invention relates to lighting equipmentof the type in extensive use for vehicles, such as automobiles, andincluding electric lamps having bayonet-type bases and sockets foraccommodating such bases.

Special purpose lamps such as turn signal, flasher and stop lamps aswell as conventional lamps are provided with such bases. The specialpurpose lamps differ in operating characteristics from conventionallamps so that it is important for safety purposes to use only thespecial purpose lamps in the locations on the vehicle requiring suchlamps.

The principal object of the invention is to provide a lighting unitincluding a special purpose lamp having a bayonet base and a socket ofsimple and effective structure to assure that only special purposebayonet-based lamps are mounted in locations where such lamps arerequired. Another object of the invention is to provide such abayonet-base and socket which requires minimum changes in existing massproduction of base-making and socket-making machines.

lnaccordance with these objects, the socket has a stop to obstruct theinsertion of a conventional bayonetbase, into a locked position in thesocket and the base of the special purpose lamp accommodates the stop inthe locked position of the lamp in the socket.

In the drawing accompanying and forming. part of this specification:

FIG. I is a perspective exploded view of an electric incandescent lampand a socket therefor,-the lamp base and the socket embodying theinvention;

FIG. 2 is a side elevational view of the lamp base shown in FIG. 1;

FIG. 3 is an end view of the base shown in FIGS. 1 and 2;

FIG. 4 is an end view showing the interior of the socket; and

FIG. 5 is a sectional view of the socket along the line 5-5 of FIG. 4with the base mounted therein shown in phantom.

Referring to FIGS. 1, 2 and 3 of the drawing, the special purpose lamp 1shown is of a conventional two-filament typehaving a high-candlepowerfilament 2 and a low-candlepower filament 3 enclosed in the usual glassbulb 4. The base 5 attached to the bulb 4 is of the usual bayonet typeexcept as described below and has a cylindrical metal shell contact 6having two pins 7 and 8 projecting laterally from diametrically oppositepoints on the periphery thereof and disposed at different distances fromthe outer end of the base 5. The two end contacts 9 and 10 of the baseare insulated from the shell 6 and from each other by the glassinsulator 11. The pairs of leading-in wires 12, 13 and 14, 15, for thefilaments 2 and 3, respectively, are so connected to the end contacts 9and 10 and the shell contact 6 of the base that the filaments may beenergized separately or together, all as well known in the art. The lampis useful as either a tail and stop lamp or a park and .turn signallamp. 7

The socket 16 shown in FIGS. 1,4 and 5 is of conventional structureexcept as described below and includes a metal shell contact 17 providedwith slots 18 and 19 of different length having ofi'set portions 20 and21 which accommodate the base pins 7 and 8, respectively, to lock thebase in the socket with shell contact 6 of the base engaging the socketshell 17 and the base end contacts 9 and 10 engaging the spring-pressedcontacts 22 and 23, respectively, of the socket as shown in FIG. 5. Thesocket contacts 22 and 23 are supported within the shell 17 by theorganic plastic'insulator 24 affixed to the shell and are electricallyconnected to the insulated conductors 25 and 26, respectively, in theusual manner, the socket shell usually being grounded when mounted byits flange 27 on a motor vehicle, for example.

Over the course of years, automatic,'high-speed base-making andlamp-making machines have been developed by the lamp industry for themass production of such bayonet-based lamps.

' The base and socket structure shown in the drawing as the preferredembodiment of the invention include a stop 28 in the form of an integralstrip on the peripheral wall of the socket shell 17 bent inwardly towardthe socket contacts and a recess 29 m the form of a land in theendcontact supporting insulator ll of the base 5 which accommodates thestop 28 to the end that the base contacts 9 and 10 effectively engagethe socket contacts 22 and 23 and compress 'the spring 30 of the socketcontacts when the lamp is locked in the socket with the pins 7 and 8engaging the offset parts of the slots, all as shown in FIG. 5 of thedrawing. The insulator of the usual bayonet base is not provided withthe recess 29 but on the contrary terminates an equal distance from theouter end of the base shell throughout its periphery. The part 31. ofthe insulator 11 (FIGS. 2 and 5) is typical of the distance between theouter end of the shell and the insulator of the usual bayonet base.

The stop 28 in the socket is so positioned with respect to the offsetportions 20 and 21 of the socket slots 18 and 19 that it engages aninsulator of the usual shape to obstruct the insertion of a lamp havinga bayonet base provided with such an insulator into the socket asufficient distance for the base pins to be locked within the offsetportions of the socket slots. Thus a lamp provided with the usualbayonet base cannot be locked onto the socket and will beforcedoutwardly of the socket by the spring-pressed socket contacts onrelease of the inserted lamp from the hand. The lamp will then eitherfall out of the socket or fail to make effective engagement with thesocket contacts. 7

I claim:

1. In a lighting unit including an electric lamp having a bayonet baseand a socket adapted to receive the base, the socket having a stopcomprising an internallyextending protrusion on the socket shelldisposed to obstruct the insertion of a conventional bayonet base into alocked position in the socket, and the base having a portionaccommodating the stop in the locked position of the base in the socketand comprising a recessed part of the base insulator.

2. A lighting unit according to claim 1 wherein the socket stop is aninwardly bent peripheral portion of the socket shell.

1. In a lighting unit including an electric lamp having a bayonet baseand a socket adapted to receive the base, the socket having a stopcomprising an internally extending protrusion on the socket shelldisposed to obstruct the insertion of a conventional bayonet base into alocked position in the socket, and the base having a portionaccommodating the stop in the locked position of the base in the socketand comprising a recessed part of the base insulator.
 2. A lighting unitaccording to claim 1 wherein the socket stop is an inwardly bentperipheral portion of the socket shell.